Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
An increase in blood \( \mathrm{CO}_2 \) or a decrease in blood pH will lead to which change in respiration?
A
Respiration will temporarily stop
B
No change in respiration
C
An increase in the rate and depth of respiration
D
A decrease in the rate and depth of respiration
Verified step by step guidance
1
Understand the relationship between blood CO2 levels, blood pH, and respiration. Increased blood CO2 leads to the formation of carbonic acid (
), which dissociates into hydrogen ions (
) and bicarbonate ions (
). This lowers blood pH, making it more acidic.
Recognize that the body has chemoreceptors in the medulla oblongata and carotid bodies that detect changes in blood CO2 levels and pH. These chemoreceptors send signals to the respiratory control centers in the brain.
Understand the physiological response: When blood CO2 increases or pH decreases, the respiratory control centers stimulate an increase in the rate and depth of respiration. This helps expel more CO2 from the lungs, reducing its concentration in the blood and restoring pH balance.
Eliminate incorrect options: 'Respiration will temporarily stop' and 'No change in respiration' are incorrect because the body actively responds to maintain homeostasis. 'A decrease in the rate and depth of respiration' is also incorrect because it would worsen the imbalance.
Conclude that the correct answer is 'An increase in the rate and depth of respiration,' as this is the body's mechanism to counteract elevated CO2 levels and decreased pH.